'Alter database XXXXX set partner timeout 30' will this kill the users in the database Can this command be run on database whilst it is being actively used.
I think you're concerned that it will kick your users out. It wont. Any database changes that need exclusive access will be blocked by connections in the database. They either timeout (the more likely option) or they continue when all other connections have left.
Some commands allow you to specify termination options:
WITH ROLLBACK AFTER integer
WITH ROLLBACK IMMEDIATE
This is detailed in the ALTER DATABASE SET Options page
You can use these to change the behaviour I originally discussed.
As you are worried, you can run the command and check if it is blocked or causes blocking then stop it if it does.